Transient tricuspid insufficiency of the newborn: a form of myocardial dysfunction in stressed newborns.

Fourteen term newborn infants have been recognized as having transient tricuspid insufficiency associated with significant perinatal stress. Five of these infants underwent cardiac catheterization for presumed congenital heart disease, but had only massive tricuspid valve insufficiency. The other nine infants were diagnosed on the basis of a murmur characteristic of tricuspid valve insufficiency and on other clinical grounds. All had a history of significant perinatal stress in the form of asphyxia with or without hypoglycemia. Frequently, congestive heart failure, persistent cyanosis, and ECG evidence of myocardial ischemia were present. Twelve of the 14 survived, and in each of them all cardiac signs and symptoms, including the murmur, spontaneously resolved. The two patients who died had histopathologic evidence of necrosis in the anterior papillary muscle of the tricuspid valve. The constant features of perinatal stress, ST-T wave abnormalities on the ECG, and spontaneous resolution of the transient tricuspid insufficiency strongly suggest that this syndrome is secondary to a reversible form of myocardial dysfunction, perhaps by affecting papillary muscle specifically. We believe that hypoxia with or without hypoglycemia precipitates the events leading to this clinical syndrome which is distinguishable from other cardiac abnormalities in the newborn by the history, distinctive murmur, and the ECG abnormalities.